Gluonic Excitations and Experimental Hall-D at Jefferson Lab

A new tagged photon beam facility is being constructed in experimental Hall-D at Jefferson Lab as a part of the 12 GeV upgrade program. The 9 GeV linearly-polarized photon beam will be produced via coherent Bremsstrahlung using the CEBAF electron beam, incident on a diamond radiator. The GlueX experiment in Hall-D will use this photon beam to search for and study the pattern of gluonic excitations in the meson spectrum produced through photoproduction reactions with a liquid hydrogen target. Recent lattice QCD calculations predict a rich spectrum of hybrid mesons, that are formed by exciting the gluonic field that couples the quarks. A subset of these hybrid mesons are predicted to have exotic quantum numbers which cannot be formed from a simple $q\bar{q}$ pair, and thus provide an ideal laboratory for testing QCD in the confinement regime. In these proceedings the status of the construction and installation of the GlueX detector will be presented, in addition to simulation results for some reactions of interest in hybrid meson searches.Comment: 5 pages, 4 figures, 1 table, contribution to the proceedings of XXII. International Workshop on Deep-Inelastic Scattering and Related Subjects, 28 Apr - 2 May, 2014, Warsaw, Polan

The STAR W Program at RHIC

The production of $W$ bosons in polarized $p+p$ collisions at RHIC provides an excellent tool to probe the proton's sea quark distributions. At leading order $W^{-(+)}$ bosons are produced in $\bar{u}+d\,(\bar{d}+u)$ collisions, and parity-violating single-spin asymmetries measured in longitudinally polarized $p+p$ collisions give access to the flavor-separated light quark and antiquark helicity distributions. In this proceedings we report preliminary results for the single-spin asymmetry, $A_L$ from data collected in 2012 by the STAR experiment at RHIC with an integrated luminosity of 72 pb$^{-1}$ at $\sqrt{s}=510$ GeV and an average beam polarization of 56%.Comment: Proceedings of the 3rd Workshop on the QCD Structure of the Nucleon (QCD-N' 2012

Response of Estuarine Fish Biomass to Restoration in the Penobscot River, Maine

Diadromous fish require both freshwater and marine habitat to complete their life cycle. Dams restrict the movement between these habitats and as a result, many populations are historically low across their range. The Penobscot River is the second largest river in Maine and once had large populations of diadromous fish and it has been the focus of mainstem dam removals, dam passage improvements, and stocking with the goal of restoring those populations. Since 2012, NOAA Fisheries has conducted surveys of the Penobscot Estuary using mobile, multi-frequency echosounders (SIMRAD EK60 split-beam 38 and 120 kHz) combined with mid-water trawl surveys to construct a time series of fish distribution to assess this large-scale restoration. Target strength (TS; dB re m2), the log10 of the backscattering cross section (σbs; m2), is an important variable in fisheries acoustics because it is used to compute biological metrics such as biomass and fish density. TS is difficult to characterize due to its stochastic properties from variability in fish physiology, orientation, behavior, depth, and size. When an assemblage consists of multiple species or multiple size classes, assigning TS to the component species or size classes is difficult due to the inability to distinguish individual components in the composite distributions. We addressed these challenges by a unique combination of techniques to characterize TS in the Penobscot River Estuary, Maine. From trawl data, we determined the estuarine species assemblage was dominated by Clupeids and Osmerids. We used single target detection and echo tracking algorithms to isolate TS values from individual fish. Next, we applied an expectation–maximization algorithm to identify components of the mixed normal TS distribution based on fish total length (TL; cm) data from trawl surveys. Finally, we used ordinary least squares regression to estimate the parameters of TS = α log10 (TL) + β. Our final parameters, α = 31.0 (SE 0.84) and β = -79.5 (SE 0.90), were similar to published studies from these species. However, our slope and intercept were higher than studies from freshwater and lower than from marine systems. These results suggest that acoustic surveys in estuarine systems with mixed species assemblages and large salinity ranges may need to develop site specific relationships between TS and fish length. The combination of these methods is an example of a novel technique to derive reproducible TS estimates in mixed pelagic fish assemblages. We used system-specific parameters to compute biomass from acoustic survey data. We assessed seasonal estimates of biomass from 2012 to 2017 a period spanning pre-restoration (2012-2014) and post-restoration (2015-2017). Biomass varied with season and year and was generally greater in summer and in post-restoration years. Biomass in pre-restoration years ranged from 9,000 to 114,000 kg per survey and 11 of 45 (23%) surveys had biomass greater than 50,000 kg. Compared to post-restoration years ranged from 23,000 to 316,000 kg per survey and 34 of 43 (76%) surveys had biomass greater than 50,000 kg. Changes in biomass were observed with changes in fish length and density where higher density resulted in higher biomass. This analysis demonstrates the utility of hydroacoustics in monitoring large-system restoration by describing multiple metrics in a complex ecosystem. The changes observed by increased density and biomass are indications that river restoration is changing the ecology of the estuary

Detecting a heavy neutrino electric dipole moment at the LHC

The milliQan Collaboration has proposed to search for millicharged particles by looking for very weakly ionizing tracks in a detector installed in a cavern near the CMS experiment at the LHC. We note that another form of exotica can also yield weakly ionizing tracks. If a heavy neutrino has an electric dipole moment (EDM), then the milliQan experiment may be sensitive to it as well. In particular, writing the general dimension-5 operator for an EDM with a scale of a TeV and a one-loop factor, one finds a potential EDM as high as a few times 10(-17) e-cm, and models exist where it is an order of magnitude higher. Redoing the Bethe calculation of ionization energy loss for an EDM, it is found that the milliQan detector is sensitive to EDMs as small as 10(-17) e-cm. Using the production cross-section and analyzing the acceptance of the milliQan detector, we find the expected 95% exclusion and 3 sigma sensitivity over the range of neutrino masses from 5-1000 GeV for integrated luminosities of 300 and 3000 fb(-1) at the LHC. (c) 2017 The Authors. Published by Elsevier B.V

A structural and physical study of sol–gel methacrylate–silica hybrids: intermolecular spacing dictates the mechanical properties

Sol–gel hybrids are inorganic/organic co-networks with nanoscale interactions between the components leading to unique synergistic mechanical properties, which can be tailored, via a selection of the organic moiety. Methacrylate based polymers present several benefits for class II hybrids (which exhibit formal covalent bonding between the networks) as they introduce great versatility and can be designed with a variety of chemical side-groups, structures and morphologies. In this study, the effect of high cross-linking density polymers on the structure–property relationships of hybrids generated using poly(3-trimethoxysilylpropyl methacrylate) (pTMSPMA) and tetraethyl orthosilicate (TEOS) was investigated. The complexity and fine scale of the co-network interactions requires the development of new analytical methods to understand how network evolution dictates the wide-ranging mechanical properties. Within this work we developed data manipulation techniques of acoustic-AFM and solid state NMR output that provide new approaches to understand the influence of the network structure on the macroscopic elasticity. The concentration of pTMSPMA in the silica sol affected the gelation time, ranging from 2 h for a hybrid made with 75 wt% inorganic with pTMSPMA at 2.5 kDa, to 1 minute for pTMSPMA with molecular weight of 30 kDa without any TEOS. A new mechanism of gelation was proposed based on the different morphologies derived by AC-AFM observations. We established that the volumetric density of bridging oxygen bonds is an important parameter in structure/property relationships in SiO2 hybrids and developed a method for determining it from solid state NMR data. The variation in the elasticity of pTMSPMA/SiO2 hybrids originated from pTMSPMA acting as a molecular spacer, thus decreasing the volumetric density of bridging oxygen bonds as the inorganic to organic ratio decreased

Situating dissemination and implementation sciences within and across the translational research spectrum

The efficient and effective movement of research into practice is acknowledged as crucial to improving population health and assuring return on investment in healthcare research. The National Center for Advancing Translational Science which sponsors Clinical and Translational Science Awards (CTSA) recognizes that dissemination and implementation (D&I) sciences have matured over the last 15 years and are central to its goals to shift academic health institutions to better align with this reality. In 2016, the CTSA Collaboration and Engagement Domain Task Force chartered a D&I Science Workgroup to explore the role of D&I sciences across the translational research spectrum. This special communication discusses the conceptual distinctions and purposes of dissemination, implementation, and translational sciences. We propose an integrated framework and provide real-world examples for articulating the role of D&I sciences within and across all of the translational research spectrum. The framework\u27s major proposition is that it situates D&I sciences as targeted sub-sciences of translational science to be used by CTSAs, and others, to identify and investigate coherent strategies for more routinely and proactively accelerating research translation. The framework highlights the importance of D&I thought leaders in extending D&I principles to all research stages